.main {
    width: 100%;
    height: 100%;
    background-image:url(../images/0.jpg);
    background-position: center center;
    background-repeat: no-repeat;
    background-size: cover;
}

.main .nav {
    height: 50px;
    opacity: 0.7; /* 50% 透明度 */ 
    background-color: grey;
}

.main .nav h3 {
    margin-left: 10px;
}


.main .dialog_containner {
    height: calc(100% - 50px);
    display: flex;
    align-items: center;
    justify-content: center;
}

.main .dialog_containner .dialog {
    background-color: rgba(255, 255, 255, 0.8);
    width: 325px;
    height: 300px;
    border-radius: 10px;
}

.main .dialog_containner .dialog h3 {
    line-height: 75px;
    text-align: center;
}

.main .dialog_containner .dialog .row {
    height: 50px;
    margin-left: 10px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.main .dialog_containner .dialog .row span {
    width: 75px;
}

.main .dialog_containner .dialog .row input {
    width: 170px;
    border: none;
    border-radius: 5px;
    margin-left: 10px;
    line-height: 25px;
    padding-left: 5px;
}

.main .dialog_containner .dialog button {
    width: 250px;
    margin-left: 40px;
    margin-top: 20px;
    margin-bottom: 15px;
    height: 30px;
    border: none;
    border-radius: 5px;
    background-color: greenyellow;
}

.main .dialog_containner .dialog button:active {
    background-color: grey;
}

a {
    display: block;
    text-decoration: none;
    margin-left: 150px;
}